Network interface modes

sakishrist · 2015-04-21 10:55:58

Hello *,

I would like to know where ethtool gets it's information on the modes (10baseT Full etc) that an interface supports.

I can always use grep in my script but was just wondering if there is maybe something in /sys that could provice that info to me (already searched there though). And human readable seems less error-prone to me.

Thanks in advance!

Trilby · 2015-04-21 11:17:06

ethtool uses system calls to get information from the kernel - it looks like this is done with functions defined in /usr/include/net/if.h.

If you want to do this in a compiled program, that should do it. But it sounds like you just want to do this from a script, so that wouldn't work.

You say you use grep - what exactly do you grep? I suspect the output of `ip` might be most useful.

sakishrist · 2015-04-21 11:46:32

Currently I grep for something like this:

ethtool $i | egrep -q "10(0(0)?)?baseT/Full"

What I need to know is that the card is not a 10G (or more) and that it is not a virtio interface. Currently that handles the situation but I was wondering if there is something cleaner.

For 10G links I could grep for

Supported ports: [ FIBRE ]

but then, virtio interfaces return nothing at all with ethtool.

I'm not really sure how to do this with ip. By the way, I am more interested in the available link modes than the currently negotiated mode.

Thanks

Trilby · 2015-04-21 12:24:33

I stand corrected, I don't know if ip can provided those details. I thought you were looking for alternatives to ethtool which I'm not familiar with aside from a quick glance at the code.

Arch Linux

#1 2015-04-21 10:55:58

Network interface modes

#2 2015-04-21 11:17:06

Re: Network interface modes

#3 2015-04-21 11:46:32

Re: Network interface modes

#4 2015-04-21 12:24:33

Re: Network interface modes

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